Preconditioning the FETI Method for Accelerating the Solution of Large EM Scattering Problems

This letter addresses the convergence rate of the Finite Element Tearing and Interconnecting (FETI) algorithm when applied to the solution of large electromagnetic scattering problems formulated via the finite element method (FEM). The FETI-H formulation is applied to derive a preconditioner for the scalar Helmholtz operator with inhomogeneous media. Examples are presented which show increased speedup over the nonpreconditioned FETI method as well as dramatic speedup as compared to a traditional diagonally preconditioned BiConjugate Gradient Method (BiCGM) solver